Quantitative identification method of complex glutenite body lithology by wave impedance

Abstract

The invention provides a method for quantitatively recognizing lithology of complicated sandstone rocks by wave impedance. The method includes the steps: determining the distribution range of different lithology on logging curve data such as array induction, density, sound wave time difference and neutron porosity according to core data and logging data; roughly distinguishing the lithology and distinguishing mud rocks, muddy sandstone rocks and sandstone rocks by the aid of an array induction curve; finely distinguishing the lithology, finely distinguishing the muddy sandstone rocks into muddy sandstones and muddy conglomerate rocks by the aid of a density curve and finely distinguishing the sandstone rocks into sandstones and conglomerate rocks; generating a wave impedance curve and further determining calcareous sandstones and calcareous conglomerate rocks by the aid of the wave impedance. Seven types of rocks are finely distinguished by the steps. The method for quantitatively recognizing the lithology of the complicated sandstone rocks by the wave impedance has good operability and is beneficial to popularization, and a feasible novel method is provided for quantitatively recognizing lithology of the complicated sandstone rocks.

Description

Technical field [0001] The invention relates to the technical field of oilfield development, in particular to a method for quantitatively identifying the lithology of complex glutenite bodies by using wave impedance. Background technique [0002] Using conventional logging curves to identify lithology, conglomerate, lime glutenite, and oil layers all have the characteristics of high resistance. The resistivity characteristics of oil layers overlap with the characteristics of conglomerate resistivity, and it is difficult to quantitatively identify most curves. Therefore, how to use conventional logging curves to quantitatively identify lithology has always been a difficult problem in the industry, which is mainly reflected in the following aspects: [0003] 1. Spontaneous potential (SP) is a commonly used curve to distinguish sandstone and mudstone, but the measurement range of different wells, different instruments, and different batches is unstable, the application effect is not g...

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Problems solved by technology

[0003] 1. Spontaneous potential (SP) is a commonly used curve to distinguish sandstone and mudstone, but the measurement value range of different wells, different instruments, and different batches is unstable, the application effect is not good, and the compaction effect is weak, which will cause SP curve The change is a gentle gradient line, and it is difficult to distinguish the sand-mudstone interface;

[0004] 2. Resistivity curves have high resistivity in conglomerate, limestone components, and well sections of oil layers, which are difficult to distinguish;

[0005] 3. The microelectrode curve is a common curve for judging lithology, but the microelectrode can only reflect the relative size, and the critical value of different lithologies is unstable and difficult to quantify

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